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(No Model.) 3 Sheets-Sheet `1.

EN Hf PRETER.

' SCREW CUTTING MACHINE. No. 309,140. Patented Deo. 9, 1884.

H MES Il mw I l o o I F3 E N l wTTNEssEs: m INV/EMDR:

EL? BY C W ATTCENEYS..

(No Model.) 3 SheetsSheet 2.

E. H. FR'ETER'.

SCREW CUTTING MACHINE.

Patented'DeC. 9', 1884.

WITNESSES: Y INVENTOR: 2% BY VLLLUM/vv 4 MM 1^ @Q- ATTORNEYS.

' (No Model.) l 3 sheets-sneer. 3.

E. H. FRETER.

SCREW' CUTTING MACHINE.

Patented Deo. 9, 1884.

ATTORNEYS.

Unirse drames Parent trice.

EDUARD HEINRICH FRETER, OF ROEDELHEIM, NEAR FRANKFORT-ON-THE A MAIN,GERMANY. i

SCREW/CUTTING NIACl-HNE.

SPECIFICATION forming part of Letters Patent No. 309,140, dated December9, 1884.

Application flcd July 25, 1883. (No model.)

To @ZZ whom it may concern:

Be it known that I, EDUARD HEINRICH FRETER, of Roedelheim, nearFrankfort-onthe-Main, Germany, have invented new and useful Improvementsin Screw-Cutting Machines, of which the following is a speciiication.

rlhis invention relates to a machine especially adapted for cuttingscrews.

Reference is to be had to the accompanying drawings, forming part ofthis spcciiication, in which similar letters of reference indicatecorresponding parts in all the figures.

Figure l is a plan view of my improved machine. Fig. 2 is a longitudinalelevation of the same. Fig. 8 is a detail side view of the ratchet-wheeland eccentric pawl for operating the clutch devices. Fig. 4 is a detailface view of the chuck. Fig. 5 is a plan view of the sliding strips onthe same. Fig. 6 is a face View of the cam'ioroperating the die-holder.Fig. 7 is a side view of the same. Fig. 8 is a c ross-sectionalelevationof the saddle and toolrest. Fig. 9 is a plan view of the under side ofthe same. Fig. l0 is a longitudinal sectional elevation'oi" wthe same.Fig. 1l isa detail side view of the lug on the die-spindle. Fig. l2 isadetail side View of the mechanism of the device for operating thegripping mechanism of the chuck. Fig. 13 is a plan and inverted plan ot'one of the catches for locking the spindle. Fig. Mis a detail view ofthe weight-and-pulley feed for the wire. Fig. 15 is a detail view of thelug on the die-spindle and the armed cam-shaft. Fig. 1G is a detail viewof armed camshaft and the pivoied leafshaped latch. i

The hollow spindle A rests on the bearingblocks B, and forms a hollowhead stock which can be revolved by means of belts passed around thestepped or cone-shaped pulley C, or directly from a motor. The eccentricdisk D, mounted on the spindle A, terminates in a pawl, D, engaging witha ratchet-wheel, E, mounted ou a spindle, j, journaled` parallel withthe spindle A in arms of the machineframe, so that the wheel E will bemoved the distance of one tooth for every revolution of the spindle A.O11 the inner end of the spindle the chuck F is secured, which is shownin Figs. 4i and 5, the face-plate being removed, which face-plate has acentral aperture through whichthe wire can be passed. A lever, 7i, ispivoted in a recess in the chuck, the recess being of such depth thatthe surface of the lever h will be Hush with the face or end of thechuck-block. At its pivoted end the lever h is enlarged to form a boss,having part of its edge iiattened. Vhen the iiattened part of the bossis over the sliding jaws b b, held in the chuck, the latter can beseparated. Vhen the rounded part of the boss is over the jaws, the upperjaw will be pressed downward and the jaws will grip the wire betweenthem. A lever, h, which is pivoted between lugs d, projecting from therim of the chuck, is provided at its pivoted end with a toothed segment,h2. A half-ring, r, is held to slide on the rim of the chuck by the lugsd and a keeper, c, which half-ring is provided at one part with alaterally-projecting fork, g, and at one end with a series ot'apertures, o, or with teeth with which the teeth of the toothed segmenth2 can engage, so that if the lever h is swung the half-ring i' will bemoved in the direction of its length on the rim of the chuck, to operatethe lever h and thereby the sliding jaws b. The tools are to be securedunder the holders l-I, fastened on a slide-rest, G, the upper part, f,of which can be moved by means of a handle, k, and the entire slide-restis movable transversely to the longitudinal axis of the lathe on thedovetailed saddle U.

On a shaft, J, journaled in the saddle U, a bevel cog-wheel, K, agrooved cam-sleeve, L, and the cog-wheel M are rigidly mounted.

From the bottom of the slide-rest G a pin, Z, projects into a groove ofthe cam L, so that a revolution of the latter causes the saddle to bemoved transversely, according to the shape of the cam-groove. Thecog-wheel M engages with a cog-wheel, R', and the motion of the latteris transmitted to the cog-wheels R2, R3, R, and P, the wheels R R2 R3being mounted to revolve on pivots projecting from the lathebed, and thewheels RA1 and lJ being mounted on pivots projecting from the secondadjustalole head-stock, B', asclearly shown in Fig. 2. When a revolutionof the spindle A effects, by means of the pawl D, a partial revolution iof the ratchet-wheel E and shaftj, the motion is transmitted by thebevel oog -wheel K',

mounted on the shaft j, to the bevel cog-wheel IOO K, and to the wheelP, provided witlrthe cam P', and the short. shaft Z, having pins w, w',and 102, for operating the sliding bar O and the die-spindle W,hereinafter described. On the shaft J are mounted two cams, Q, which,when rotated, press upon two levers, R, pivoted to swing, and thusadapted to lift the pieces S, held to move up and down in the saddle U'.The pieces S are provided with small frictionrollers o' at their upperends, and as soon as the pressure from the lever Bor the cams Q.respectively, decreases, the pieces S are pressed down by suitablesprings. (Not shown.) When one or the other of the pieces S is lifted byits lever R, resistance is offered to the lever h orh, respectively,which rotates with the chuck` F, whereby the chuck is either closed oropened to grasp or release the wire-that is, it is closed when the leverh strikes against a piece, S; but when the lever h finds the resistance,the chuck is opened as the half-ring r is moved by the lever h', and thelever h, being between the prongs of the fork g of the ring r, is alsomoved, so that the pressure exerted by the lever l1, upon the jaws b bistaken off and the jaws are released. The chuck is opened to allow of thewire being pushed through it as soon as a screw is threaded and cut olf,and is closed as soon as sufficient length of material has been passedthrough lit for the next screw. The screw-cutting dies are in thespindle YV, which rests on the second head-block, B B', and is pulledforward in the direction of the arrow, Fig. l, by the screwcutting diesit carries in proportion as they cut the thread on the screw being made.The forward movement of the said spindle compresses the spring B, whichserves to draw the spindle back to its original position as soon as thereverse motion imparted to the spindle from the pulley T has unscrewedthe screw-dies from the finished screw. The pulley Tis mounted looselyon the said headblock B B, but is not movable endwise thereon.

y On the spindle Va pulley or friction-disk, V, provided with a sleeve,V, is mounted, which pulley is movable endwise, but is not free to turnon the spindle. The sleeve V is provided with' an annular groove, 0L,into which the shanks Yof a fork, m, pass, which is fixed to a parallelrod, O, adapted to b; moved to and fro longitudinally on a suitablerest, and is guided by slot-s p p.

From the under side of the rod O a lug, q, projects.

From the die-spindle NV a lug, t, projects, which lug is provided withthe projection g. To the said lug tthe slotted plate g2 is adjustablysecured.

u 'o are catches pivoted to a iixed support,

'and Aengaging the lug tand plate g2 of the spindle V, respectively,when the said spindle is in its normal position. Thecatch u is alsopivoted to the rod O, so that' the said catch, when the rod O is pushedfrom right to left, will be moved away from under the lug t. The catch'o is provided with the curved slot t', to receive the pin w of theshaft Z, and a projection, c2, to be engaged by said pin, for a purposehereinafter described. The catch is also provided with a ilange engagingthe slotted plate g2 on the lug t of the spindle'V. Vhen the catches u cengage the lug tand plate g', the spindle is preventedfrom rotating. Thewire is fed into the hollow head-stock spindle A by the apparatus shownin Fig. 14. This feeding apparatus consists of a plate, 4, sliding uponrod 5, projecting' from the frame of the machine, and connected to acord, l, which passes over pulleys 2 and has a weight, 3, attached toits end, so that as the plateis drawn along on the rod by theweight thewire will be fed into the spindle. On one slide-rest the shaping-tool isplaced, and lon the other rest the tool for cutting off the nished screwis placed. The transverse, shaft J is common to both slide-rests, andthe construction is similar in both, except that one part is without thecog-wheels M and K.

The operation is as follows: 1f the chuck F is open-fthat is, if thejaws b b are not pressed together by the lever h-the wire, the end ofwhich has been shaped according to the desired length of the screwexclusive of the head, is moved forward by the feeding-device shown inFig. let until it strikes against the cutting-dies on the spindle W. Atthis moment the pin w of the shaft Z moves in front of the projectiong', which is' secured tothe die-spindle WV, as shown in Fig. 15, andpushes the same forward a little, and at the same time the wire'ispushed back to the exact length of the screw to -be made by the forwardmovement of the spindle. Then the corresponding piece Sfin the saddleIl, is lifted and offers resist-ance to the lever 7i, whereby the wireis grasped firmly by the jaws b in the chuck. The piece S then fallsback to its normal position, and the slide-rest with the shaping-tool,is moved against the wire by the action of the grooved cam. Vhile thewire is being turned off to the required thickness for the next screw,the cutting apparatus is pressed rmly against the wire by means of thesecond and longer pin, w?, of the shaft Z engaging the projection g', sothat the thread-cutting apparatus grasps the rotating wire, which screwsitself into the cutting apparatus, and thus the thread and the head ofthe first screw are cut at the same time that the length of the nextscrew is turned, by means of the shaping-tool on the slide-rest. Duringthe cutting of the thread the cuttingdies are pulled forward, and as theplate y? does not leave the catch o the latter still prevents therotation of the die-spindle. When the thread is finished, theslide-rest, with the tool, having done its work, recedes, being moved bythe cam L. In the meantime the pin @o of the shaft Z has entered theangular slot of the catch and c, by its engagemeht with the said slotand the projection 'o2 the catch o is carried away from the plate g2. At

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the same time the piece O is pushed forward by the action of the cam Pof the wheel P, the projection of the cam pressing against the lu g Q.Thereby the friction-plate V is pushed into the loose pulley T, and thediespindle "W now rotates at a considerable higher speed than thehead-stock A,as the pulley T is connected by a belt with thepower-shafting or directly with a motor, and thus the completed screwscrews itself out of the cuttingsdies, and the spindle XV is then drawnback into its former position by the spring B2. The cam of the wheel Phas now passed away from under the projection of the parallel rod O, andthis rod is also brought back into its former position vby a spring. Thefrictionplate V then releases the pulley T. The slot t in the catch cbeing curved, the latter will be slightly moved on its pivot inproportion as the pin w, attached to the shaft Z, passes through itduring part ofthe revolution of the said shaft Z, as shown in Fig. 16.The pin w having left the slot 'o' of the catch o, the said catch o ispushed partly under,while its flange o2 is pushed partly over the lug tby a spring, Y, and the entire mechanism is in its former position.` Thegrooved cams,which cause the motion of the slide-rest, can be changed,if desired, and the movements of the slide-rests are thus variedaccording to the position of the groovedcams on the shafts. Theprojection q,secured to the die'spindleVJsadjustable to regulate thelength of the screw-Unread, as the farther away from thchcad of thespindle XV carrying the screw-cutting dies thc projection g' is situatedthe sooner it will come in contact with the revolving pin w', andtherefore the screw cut will be longer than if the projection g issituated nearer to the die-head.

4o The second head-stock, B B, is adjustable on the bed of the lathe, asis also the wheel R, through which the revolution of the wheel Rt istransmitted to the wheel R4, their relative positions to each otherbeing determined by the length and size of the article being made. Thelonger the article the farther apart they have to be put; the shorterthe article the nearer together.

Having thus fully described my invention, l claim as new and desire tosecure by Letters Patentl. A screwcutting machine consisting of thehollow head-stock spindle A, in co1nbination with the pawl D, the chuckF, the sliding rests G G, the die-spindle XV, having the lug tandprojection g, the loose pulley T, the friction-plate V, t-he parallelrod O, catches u and o, the ratchet-wheel E, the shaft j, the shaftJ,tl1e bevcl`wheels K K', the cog-wheels M, R', it?, Pf, ql", and P, thelatterbeing provided with a cam, and shaft Z, having proj ccting pins,substantially as set forth.A

2. In a screw-cutting machine,the chuck F, consisting of a circularpiece having arecess, a, combined with a movable half-ring, 1, thelevers It h, and the jaws b b, substantially as herein shown anddescribed.

3. In a screw-cutting machine, theslide-rest consisting of the piecesj', G, G, and U, and the shaft J, combined with the bevel cog-wheel li,the grooved cam L, the cog-wheel M, the cams Q Q, the levers R, andmovable pieces S, substantially as herein shown and described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

, EDUARD HEINRICH FRETER.

Vfitnesses:

FRANZ Hnssnncnnn, Josnrir PATRICK.

